Question

如何在void pf下添加文件路径参数？（我是C ++的新手）

正如您可能看到的那样，我正在考虑强制某个文件的缓存进入物理内存。

代码：

#include <windows.h>
#include <cstdio>

void pf(const char* name) {

HANDLE file = CreateFile(name, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE, 0,   OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
if(file == INVALID_HANDLE_VALUE) { printf("couldn't open %s\n", name); return; };

unsigned int len  = GetFileSize(file, 0);

HANDLE mapping  = CreateFileMapping(file, 0, PAGE_READONLY, 0, 0, 0);
if(mapping == 0) { printf("couldn't map %s\n", name); return; }

const char* data = (const char*) MapViewOfFile(mapping, FILE_MAP_READ, 0, 0, 0);

if(data)
{
    printf("prefetching %s... ", name);

    // need volatile or need to use result - compiler will otherwise optimize out whole loop
    volatile unsigned int touch = 0;

    for(unsigned int i = 0; i < len; i += 4096)
        touch += data[i];
}
else
    printf("couldn't create view of %s\n", name);

UnmapViewOfFile(data);
CloseHandle(mapping);
CloseHandle(file);
}

int main(int argc, const char** argv)
{
if(argc >= 2) for(int i = 1; argv[i]; ++i) pf(argv[i]);
return 0;
}

Answer 1

你的问题措辞很差，显然是因为你对C ++几乎一无所知。这将为您提供一种入门方式。用这个替换主函数：

int main(int argc, const char** argv)
{
    pf("C:\\SomeDir\\SomeFile.ext");
    return 0;
}

然后得到一本书，开始学习字符串和函数的工作原理。

添加文件路径参数？

1 个答案: